Multi-purpose precision bending machine



June 26, 1956 R. G. BEALS "2,751,960

MULTI-PURPOSE PRECISION BENDING MACHINE Filed April 11 1951 2 Sheets-Sheet 1 1? gig-: 22 12W 16 6 Roscoe QBeaZs June 26, 1956 R. G. BEALS 2,751,960

MULTI-PURPOSE PRECISION BENDING MACHINE Filed April 11, 1951 2 Sheets-Sheet 2 United States Patent MULTI-PURPOSE PRECISION BENDIN G MACHINE Roscoe G. Beals, De Kalb, Ill. Application April 11, 1951, Serial No. 220,403

12 Claims. (Cl. 153-39) This invention relates to a multi-purpose precision bending machine and has for its principal object the provision of a machine of relatively simple and economical design and construction and one which may be quickly and easily set by hand for different jobs in the bending of wire, rod, strap, bar or tube material of various sizes, the present machine beingintended for use wherever it is desired to form and duplicate a large variety of parts and pieces without the time delay and expense otherwise involved in the preparation of special blanking and forming dies, and also make it possible to produce shapes and profiles that are either impractical or impossible to produce at all with regular production dies.

I am aware that various precision benders have been available heretofore, but they were invariably too complicated and expensive in design and construction and required expert operators to set them up for each new job and the set up operations took too long. Also, in most prior machines, the design and construction was such that it was not practical to do precision bending on certain widths and thicknesses of material, particularly if a rather sharp bend was needed or if the bend was to be through as much as 180 or more. It is therefore the principal object of my invention to provide a machine that either avoids or at least minimizes these objections inherent in the earlier machines.

In certain earlier bending machines a profusion of accurately spaced holes was needed in the die plate or plates to enable the operator to set a holding pin in different radially spaced relationship to a central mandrel and, of course, the mere fact that such holes were provided, imposed a definite limitation upon the range of widths of material that could be bent. It is, therefore, another important object of my invention to provide a bending machine inwhich holding jaws are fixed as to location in the opposed die plates and the central mandrel is in holders that are slidably adjustable diametrically of the die plates with infinite adjustability, each holder being in a slide which is backed up at the opposite end from the jaw by a wedge-shaped cam that is slidably adjustable circumferentially with respect to the the plate and transversely relative to the outer end of the slide so as to hold the mandrel firmly in any adjusted position relative to the jaw, the slides in both die plates being similarly adjustable so that any width of material within the limits of the machine can be accommodated, and the mandrel being also adjustable transversely of the slides to suit difierent diameters of mandrels, these adjustments taking only a few seconds.

In certain prior designs of bending machines only one die plate was provided, the mandrel and cooperating holding pin projecting from the plane of the die plate. That was all right for certain simple bending operations, but not where it was important that the bent material be kept absolutely fiat and true. It is, therefore, another important object of my invention to provide 'two opposed adjustable die plates and to have the holding jaws carried by suchpla'tes and which cooperate with the stationary 2,751,960 Patented June 26, 1956 central mandrel slidable endwise parallel to the mandrel between said plates, each jaw being under spring pressure in its supporting plate toward engagement with the other plate. This enables adjusting the machine for difierent widths of material measured parallel to the mandrel, and, in that connection, I prefer to provide an arbor-like frame in which the upper or outer one of the two plates is screw threadedly adjustable relative to the other plate, the two plates, in other words, being movable toward or away from one another, like the jaws of a vise, the slidably adjustable holding jaws in these plates adjusting themselves automatically as the machine is opened up more and more to accommodate larger sized material.

The invention is illustrated in the accompanying drawings, in which Fig. 1 is a side view of a multi-purpose precision bending machine made in accordance with my invention;

Fig. 2 is a plan view of the lower one of the die plates depicted in Fig. 1;

Fig. 3 is a cross-section on the line 3-3 of Fig. 4, the view being inverted relative to the position shown in Fig. 1.

Fig. 4 is an inside plan view taken mainly on the line 44 of Fig. 3, showing the back of the work engaging or front half of the die plate from which the supporting or back half has been removed so as to disclose in plan view the mandrel holder slide together with its L-shaped projections and its cooperating adjusting cam, and also disclose the holding jaw from the rear and the springs that cooperate with it, as well as the connection of one of the operating handles, the view being turned through from that shown in Fig. 3; and

Fig. 5 is a fragmentary, side elevational view of the pivot post portion of the lower die plate and mandrel assembly looking to the right in Fig. 3, illustrating the detachable connection between the post and the mandrel holder and between the mandrel holder slide and the post.

The same reference numerals are applied to corresponding parts throughout the views.

Referring to the drawings, the reference numeral 6 in Fig. 1, designates the stationary or fixed half of the arbor frame and 7 the adjustable half, the latter being guided by means of the ,post 8 relative to the stationary half 6 and having a screw threaded part (not shown) which enables adjusting the part 7 like the jaw of a vise toward and away from the part 6 as indicated by the double-headed arrow by manual rotation of the handle 9. Die plates, indicated generally by the reference numerals 1 3 and 11, are supported for rotation on the parts 6 and 7 by means of posts 12 and 13, respectively, and have handles 14 and 15 by means of which they are adapted to be turned relative to one another in opposite directions, or one is adapted to be held while the other is turned relative to it. The spacing of the die plates 11 and 11 is in accordance with H dimension of the material to be bent, as indicated in Fig. 1. H refers to heighth, as distinguished from the W dimension indicated in Fig. 2, which stands for the width dimension of the material to be bent, the latter being the distance 'b'etween the central mandrel 16 and the bending lugs 'or jaws 17 and 13. The jaws 17 and 18 slide in holes 19 provided therefor in the die plates 10 and 11 and each jaw has a pair of coiled compression springs 20 urging thesame outwardly toward engagement with the other die pl'ate, jaw 17 being urged upwardly toward die plate '11 from plate 10, and jaw '18 being urged downwardly toward die plate 10 from plate 11. Flanges are provided in opposite sides of the inner ends of each jaw, as indicated at 17 in Fig. '2, to limit outward movement of the jaws so they wont 'be ejected from their holes in the event the die plates are too widely separated. In that 'way the jaws are self-adjusting and follow the die plates in their adjustment. It goes without saying that the con- "fronting 'faces'of the two'die'plates 10an'd '11 are parallel and smooth and are adapted to hold the work against distortion out of a proper plane in the bending of the work to whatever form is desired.

The two die plates are-of substantially identical construction, so the description of one will sufiice for both. .The loweror inner die plate is the one illustrated in Figs. 2, 3 and 4. Excepting for the provision of an annular shoulder provided on the post 13 or a collar secured on the projecting end portion of said post to define such a shoulder for support of the die plate 11 where it is disposed above the plate 10, the two plates are substantially alike. Each die plate is made in two halves, as indicated at 21 and 22. In each half is an arcuate groove 23 struck with the center of the plate as its center and these registering grooves 23 provide a T-shaped guideway for a circumferentially adjustable wedge-shaped cam 24 which has arcuate flanges 25 struck on the same radius as the grooves 23 and slidably guided in said grooves. Extending substantially diametrically of the two halves 21 and 22 are other grooves 26 on opposite sides of a slot 27, and a slide 28 carrying a mandrel holder 29, is slidably received in the slot and guided in the grooves for adjustment in a generally radial direction relative to the die plate. Although member 28 is slidable longitudinally of the grooves 26 and slot 27 in the die plate, member 28 carrying the mandrel holder 29 and mandrel 16 is actually held stationary during adjustment and the die plates carrying the jaws 17, 18 are slid radially whereby to adjust the jaws 17 and 18 toward and away from the mandrel 16, according to the width dimension W of the work to be bent. The rounded end 38 on the slide 28 has abutment with the surface of the wedge-shaped cam 24 so that the cam serves to back up the slide and hold the die plates and jaws 17, 18 in any adjusted position relative to the stationary slide and mandrel 16. Infinite adjustability is afforded, and the adjustment takes only a second or two, because each cam 24 is adapted to be slid forwardly by means of a radially projecting handle 31 to bring the cam into abutment with the rounded end of the slide once the 'die plates have been moved to approximately the desired position. In an opening up adjustment the operator first backs the cam 24 away from the slide and thereby leaves the die plates free to move in either direction with respect to the slide, and then the jaws 17, 18 are moved away from the mandrel 16 to the correct W dimension, after which it is, of course, a simple matter to slide the cam 24 up into abutment with the outer end of the slide to back it up properly and maintain the adjustment. When the adjustment is to be in the opposite direction, that is, to reduce the width dimension W, the cams 24 can be moved to effect the adjustment directly. Viewing Fig. 4, movement of cam 24 in a counter-clockwise direction will cause the die plate 10 on slide 28 to move to the right and accordingly adjust the jaw 17 toward the mandrel holder 29. A peripheral slot 32 is provided in each of the die plates through which the handle 31 for adjusting the cam 24 projects for manual operation.

Each of the mandrel holders 29 has a hole 33 provided therein and these holes 33 are, of course, in register to slidably receive the mandrel 16. Each of the two holders 29 is of any suitable non-circular form in cross-section so as to be non-rotatable in the hole 34 provided therefor in the pose of fastening the mandrel holder to the post 12, or 13, slide and permit fastening the same in place, each with a single screw 35. The one screw 35 serves the double purpose of fastening the mandrel holder to the post 12, or 13, as the case may be, and also fastening the slide to the post. Each of the slides 28 has a pair of L-shaped projections 36, as shown in Figs. 4 and 5, and these projections are slidably received in parallel grooves 37 provided in the associated post and consequently when the screw 35 is threaded into the mandrel holder 29 and tightened, the

.post is held in rigid relation to the slide 28, and the holder 29 is also fixed in relation to the post. The sliding key connection afforded by the projections36 working in grooves 37 keeps the post 12 from dropping out when screw 35 is removed to permit substitution of another mandrel holder 29 with a diflerent size mandrel hole in it. When the screw 35 fastens the mandrel holder 29 to the post 12, the post is then rigid with the slide 28, and the slide 28 with the post 12 remain stationary as the die plate 10 and jaw 17 are adjusted laterally to whatever position of adjustment is desired depending upon the width dimension W, as should be clear from inspection of Fig. 4.

If a difierefit size mandrel 16 is needed, another set of holders 29 can be substituted having the appropriate size holes 33. A key projection 38 is preferably provided on the inner end of each holder 29 to engage in a keyway 39 provided in the adjacent end of the associated pivot post 12 or 13, whereby to fasten the holder in a more rigid relationship to the post when the associated screw 35 is tightened. The tightening of the screw 35 also fastens the post in rigid relationship to the associated slide 28, as stated before. I have found it important in operating with difierent sizes of mandrels to change the location of the mandrel 16 transversely relative to the slides 28, as indicated by dimension X in Fig. 2. I found that the smaller the size of mandrel the closer its center should be to the edge of the slides, so as to insure smaller wire wrapping snugly around the mandrel in bending. While the holders 29 could conceivably be made slidably adjustable, as by threaded means, transversely of the slides 28 to get the desired result, I believe it is simpler to get this result byproviding the key projection 38 on each holder 29 at the appropriate location measured transversely of the end of the holder and transversely of the slide so as to obtain the appropriate dimension X for each size mandrel. Without implying any limitations, but merely by way of example, in a device where the range of mandrel diameters is to the dimension X is preferably .050", which calls for only a slight difference in the location of the key projections 38 on each pair of holders 29 for the 'end portion of the material being bent moves with the one die plate in its rotary motion and said end portion wmoves relative to the other die plate.

The bending jaws or lugs 17 and 18 are always held under pressure of springs 20 in contact with the plates 10 and 11, and at the outset are in aligned relation, as indicated in Fig. 2, where the companion jaw 18 on plate 11 is indicated in dotted lines in alignment with jaw 17 on plate 10, which appears in full lines in this plan view. The appropriate size mandrel 16 is selected according to the radius of the bend, and, of course, the holders 29 for that size mandrel are inserted in the slides 28, thereby obtaining the right X dimension automatically. The jaws 17 and 18 are spaced from mandrel 16 a distance W, which is the width dimension of the material to be bent. The cam 24 in each of the die plates 10 and 11 serves to back up the slide 28 positively, holding the work tightly between the mandrel 16 and the jaws, so that when the die plates 10 and 11 are turned in opposite directions by means of handles 14 and 15, or one plate is turned while the other is held against turning, the work is thereby bent around vH or W. The die plates prevent distortion and twisting of the material as it is bent through any desired angularity, up to 180 or more.

It is believed the foregoing description conveys a good understanding of the objects and advantages of my invention. The appended claims have been drawn to cover all legitimate modifications and adaptations.

I claim:

1. In a bending machine, a frame carrying a pair of spaced parallel die plates between which the material to be bent is adapted to be placed, said plates being adjustable toward or away from one another to suit one dimension in the section of the material to be bent, two bending jaw members slidable under spring pressure in guides provided therefor in said die plates parallel to the axis of rotation of said plates, the one jaw being spring pressed relative to one plate toward engagement with the other plate, and the other jaw being spring pressed relative to the latter plate toward engagement with the former plate, each of said plates having a substantially diametrically extending guideway provided therein and a slide positioned in said guideway, a central mandrel supported in registering axial guides provided in said slides, said plates and jaws being adjustable relative to said mandrel by a sliding adjustment between said plates and slides, the spacing of the central mandrel relative to the jaws being in accordance with the transverse dimension of the section of the material to be bent, means for maintaining the slides and plates in their adjusted position, and means for turning one die plate relaitve to the other.-

2. A bending machine as set forth in claim 1 wherein the means for maintaining the slides and plates in their adjusted position comprises Wedge-shaped cams engageable directly with the ends of the slides and slidable in guides provided therefor in said plates in transverse relation to the guides for said slides.

3. A bending machine as set forth in claim 1 wherein the means for maintaining the slides and plates in their adjusted position comprises arcuate wedge-shaped cams engageable directly with the ends of the slides and sii-dable circumferentially of the plates in guides provided therefor in said plates in transverse relation to the guides for said slides.

4. in a bending machine, a frame carrying a pair of spaced parallel die plates between which the material to be bent is adapted to be placed, said plates being adjustable toward or away from one another to suit one dimension in the section of the material to be bent, two bending jaw members slidable under spring pressure in guides provided therefor in said die plates parallel to the axis of rotation of said plates, the one jaw being spring pressed relative to one plate toward engagement with the other plate, and the other jaw being spring pressed relative to the latter plate toward engagement with the former plate, each of said plates having a substantially diametrically xtending guide way provided therein and a slide positioned in said guideway, a pivot post for each plate in fixed relation to the slide thereof and supporting the plate for rotation by engagement in a bearing in the frame, a central mandrel supported in registering axial guides provided in said slides, said plates and jaws being adjustable relative to said mandrel by sliding action of said plates on said slides, the spacing of the central mandrel relative to the jaws being in accordance with the transverse dimension of the section of the material to be bent, means for maintaining the plates in adjusted position on said slides, and means for turning one die plate relative to the other, or turning the plates simultaneously in opposite directions.

5. In a bending machine, a frame carrying a pair of spaced parallel die plates between which the material to be bent is adapted to be placed, said plates being adjustable toward or away from one another to suit one dimension in the section of the material to be bent, two bending jaw members slidable under spring pressure in guides provided therefor in said die plates parallel to the axis of rotation of said plates, the one jaw being spring pressed relative to one plate toward engagement with the other plate, and the other jaw being spring pressed relative to the latter plate toward engagement with the former plate, each of said plates having a substantially diametrically extending guideway provided therein and a slide positioned in said guideway, a mandrel holder block inserted in a recess provided therefor in the middle portion of each of said slides, a pivot post slidably connectable with each of said slides, means for fastening the mandrel holder block in each slide with the associated pivot post so as to fasten the post in rigid relation to its associated slide, each pivot post being received in a bearing provided therefor in said frame for rotary support of the associated plate, a central mandrel supported in registering axial holes provided therefor in said mandrel holder blocks, said plates and jaws being adjustable relative to said mandrel by sliding action of said plates on said slides, the spacing of the central mandrel relative to the jaws being in accordance with the transverse dimension of the section of the material to be bent, means for maintaining the plates in adjusted position on said slides, and means for turning one die plate relative to the other.

6. In a bending machine, a frame carrying a pair of spaced parallel die plates between which the material to be bent is adapted to be placed, two bending jaw members in said die plates, each of said plates having a substantially diametrically extending guideway provided therein and a slide positioned in said guideway, a central mandrel supported in registering axial guides provided in said slides, said plates and jaws being adjustable relative to said mandrel by sliding action between said plates and slides, the spacing of the central mandrel relative to the jaws being in accordance with the transverse dimension of the section of the material to be bent, means for maintaining the slides and plates in their adjusted position, and means for turning one die plate relative to the other.

7. A bending machine as set forth in claim 6 wherein the means for maintaining the slides and plates in their adjusted position comprises wedge-shaped cams engageable directly with the ends of the slides and slidable in guides provided therefor in said plates in transverse relation to the guides for said slides.

8. A bending machine as set forth in claim 6 wherein the means for maintaining the slides and plates in their adjusted position comprises arcuate wedge-shaped cams engageable directly with the ends of the slides and slidable circumferentially of the plates in guides provided therefor in said plates in transverse relation to the guides for said slides.

9. In a bending machine, a frame carrying a pair of spaced parallel die plates between which the material to be bent is adapted to be placed, two bending jaw members in said die plates, each of said plates having a substantially diametrically extending guideway provided therein and a slide positioned in said guideway, a pivot post for each plate in fixed relation to the slide thereof and supporting the plate for rotation by engagement in a bearing in the frame, a central mandrel supported in registering axial guides provided in said slides, said plates and jaws being adjustable relative to said mandrel by sliding action of said plates on said slides, the spacing of the central mandrel relative to the jaws being in accordance with the transverse dimension of the section of the material to be bent, means for maintaining the plates in adjusted position on said slides, and means for turning one die plate relative to the other or turning the plates simultaneously in opposite directions.

10. In a bending machine, a frame carrying a pair of spaced parallel die plates between which the material to be bent is adapted to be placed, two bending jaw members in said die plates, each of said plates having a substantially diametrically extending guideway provided therein and a slide positioned in said guideway, a mandrel holder block inserted in a recess provided therefor in the middle portion of each of said slides, a pivot post slidably connectable with each of said slides, means for fastening the mandrel holder block in each slide with the associated pivot post so as to fasten the post in rigid relation to its associated slide, each pivot post being received in a bearing provided therefor in said frame for rotary support of the associated plate, a central mandrel supported in registering axial holes provided therefor in said mandrel holder blocks, said plates and jaws being adjustable relative to said mandrel by sliding action of said plates on said slides, the spacing of the central mandrel relative to the jaws being in accordance with the transverse dimension of the section of the material to be bent, means for maintaining the plates in adjusted position on said slides, and means for turning one die plate relative to the other.

11. In a bending machine, a frame carrying a pair of spaced parallel die plates between which the material to be bent is adapted to be placed, said plates being adjustable toward or away from one another to suit one dimension in the section of the material to be bent, two bending jaw members slidable under spring pressure in guides provided therefor in said die plates parallel to the axis of rotation of said plates, the one jaw being spring pressed relative to one plate toward engagement with the other plate, and the other jaw being spring pressed relative to the latter plate toward engagement with the former plate, each of said plates having a substantially diametrically extending guideway provided therein and a slide positioned in said gnideway, a central mandrel supported in registering guides in said slides, which guides are located diflEerently spaced with respect to the adjacent lateral edge of the slides for different diameters of mandrels, said plates and jaws being adjustable relative to said mandrel by sliding action between said plates and slides, the spacing of the central mandrel relative to' the jaws being in accordance with the transverse dimension of the section of the 'material to be bent, means for maintaining the slides and plates in their adjusted position, and means for turning one die plate relative to'the other. V

12. In a bendingmachine, a frame carrying a pair of spaced parallel die plates between which the material to be bent is adapted to be placed, two bending jaw members in said die plates, each of said plates having a sub stantially diametrically extending guideway provided therein and a slide positioned in said guideway, a central mandrel supported in registering guides in said slides, which guides are located differently spaced with respect to the adjacentlateral edge of the slides for difierent diameters of mandrels, said plates and jaws being adjustable relative to said mandrel by sliding action between said plates and slides, the spacing of the central mandrel relative to the jaws being in accordance with the transverse dimension of the section of the material to be bent, means for maintaining the slides and plates in their adjusted position, and means for turning one die plate relative to the other.

References Cited in the file of this patent UNITED STATES PATENTS 1,319,798 Saterlee Oct. 28, 1919 1,836,502 Poole Dec. 15, 1931 1,993,970 MacMurray Mar. 12, 1935 2,471,083 Tuttle May 24, 1944 FOREIGN PATENTS 482,204 France Dec. 5, 1916 

